1. Field of the Invention
The present invention relates to an optical recording and reproducing apparatus and an optical recording and reproducing method.
2. Description of the Related Art
When a mark is recorded at high speed in an optical recording medium in which high-density recording is possible such as a digital video disk, heat in an end portion of the mark recorded may be conducted through a space portion continuing to the end portion and affect an increase in temperature of in a beginning portion of a mark to be formed next. The heat may be conducted from a beginning portion of the mark recorded through a space portion continuing to the beginning portion and affect a cooling process of the end portion of the mark already recorded. Such an influence on a mark formation process due to heat conduction is called thermal interference. In particular, when a space length immediately in front of or immediately behind the mark recorded is small, the heat interference is conspicuous.
When the thermal interference occurs, an edge position of the mark fluctuates and an error ratio increases when information is reproduced. Thus, in the past, it is considered that a method of controlling a laser adapted to an optical recording medium to be used is necessary in order to realize high-speed recording in the optical recording medium.
To solve the problem and record information in the optical recording medium while maintaining a satisfactory recording quality, a method of setting a recording parameter forming a recording waveform of the laser (hereinafter referred to as write strategy) and recording the information on the basis of the write strategy is used. It is known that the recording quality has a close relation with a dye, a material, the thickness of the dye, a shape of a groove, recording speed, and the like of the optical recording medium. The write strategy has to be optimally adjusted taking into account these factors.
As examples of the related art, JP-A-2004-185796 and JP-A-2004-335079 can be cited.